The amount of μ-calpain is significantly higher in the B-CLL cells than in healthy lymphocytes.

The expression of μ-calpain was assessed by Western blotting in the samples of B-CLL cells and of PBLs and enriched CD3⁻ cells of healthy controls. (A) A representative blot of 1 of 3 experiments performed (containing data from 3 healthy people [CD3⁻ 1 through CD3⁻ 3] and 3 different, age-matched B-CLL patients [B-CLL1 through B-CLL3]). Upper row: expression of μ-calpain; lower row: expression of F-actin in the same material as described in “Patients, materials, and methods.” (B) Graphical summary of all 3 experiments. Bars represent arithmetical means of the amount of protein in the μ-calpain bands, expressed as arbitrary densitometric units per milligram of cellular protein ± SEM. Asterisks indicate statistical significance of difference (Student t test) between the adjacent bars (B-CLL, CD3⁻) at the level of P < .01 (*).